The president is caught on tape saying he'll have 'flexibility' on the issue after the election. Critics question his stance, and later, he says he's not trying to 'hide the ball.'

President Obama and Russian President Dmitry Medvedev after their meeting… (Jewwl Samad / AFP/Getty…)

SEOUL — President Obama has said he plans to continue negotiations with Russia this year involving a U.S. missile defense system to protect Europe and is not trying to "hide the ball" in dealing with the matter.

Obama said Tuesday that he wants to spend time this year working through technical issues with the Russians.

In a private conversation made public by a live microphone, President Obama on Monday appeared to be putting off diplomatic talks with Russian leaders about the controversial missile defense system until after the November election, prompting quick attacks from the president's Republican rivals.

Obama was seen on video in a casual chat with Russian President Dmitry Medvedev at a nuclear security summit in Seoul. On the tape, Obama leans toward Medvedev and can be heard giving him a message for the once and future Russian president, Vladimir Putin.

"On all these issues, but particularly missile defense, this can be solved," Obama said. "But it's important for him to give me space.

"This is my last election. After my election I have more flexibility."

The exchange, its air of secrecy enhanced by the muffled audio, raised alarm among Obama's critics about his long-term commitment to the missile defense system. The U.S. has promoted it as a shield to protect Europe from missile attacks by Iran. The Russians fear it's aimed at them, and opposition to the missile shield was a major theme of Putin's recent presidential campaign.

Putin, who previously served two four-year terms as president, won a new six-year term March 4 in an election that critics charge was flawed. He will succeed Medvedev, who replaced him in 2008 when term limits prevented Putin from seeking a third successive term.

Mitt Romney, the front-runner for the Republican nomination, accused Obama of "pulling his punches with the American people" and obscuring his plans for the missile defense system.

House Speaker John A. Boehner (R-Ohio) said "we look forward" to hearing what the president meant by "more flexibility" when he returns from South Korea.

John Bolton, ambassador to the United Nations during the George W. Bush administration, called Obama's comments a "fire bell in the night," which signaled not only that Obama would scale back the missile defense program, but also that he might be planning to give ground on a range of national security priorities.

"There's huge cause for concern here," Bolton said.

Obama is too much of "a politician to entirely show his hand in the first term, but it would be open season" if he is reelected, Bolton said.

By afternoon, the Republican National Committee had created a video ad with the subtitle, "What Obama tells world leaders when he thinks you aren't listening."

White House aides said the president was still "deeply invested" in the missile defense system.

Deputy national security advisor Ben Rhodes said after the recording became public that the two leaders had been talking about Russia's objections to the missile defense system and agreed to talk later because of political concerns on both sides. The two sides have been trying in vain for years to reach a breakthrough on missile defense, and no one was expecting a dramatic change at this week's nuclear summit.

What Obama meant by "flexibility" was unclear. Some analysts speculate the U.S. might try to win over the Russians by showing them classified data to prove that the system could take down Iranian launches but not Russian intercontinental ballistic missiles. Few experts think that would convince the Russians.

Public broadcast of the private exchange provided a rare glimpse at the candor world leaders sometimes exhibit at such high-level meetings. Last year, journalists overheard Obama and French President Nicolas Sarkozy talking about Israeli Prime Minister Benjamin Netanyahu. Sarkozy said he "can't stand" Netanyahu.